The White ant (Termes favipes koll)

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Circular no. 50, Second series.

United States Department of Agriculture,

DIVISION OF ENTOMOLOGY,

L. O. Howard, Entomologist.

THE WHITE ANT

( Termes flavipes Koll. ) .

L* I B R A R V

RECEIVED

JUL 17 1902

U. S. Department of Agriculture.

By C. L. Marl att,
First Assistant Entomologist.

[Revised reprint from Bulletin No. 4, New Series, Division of Entomology, U. S. Department of

Agriculture, pp. 70-76.]

No insect occurring in houses is capable of doing greater damage
than the one under consideration. Its injuries are often hidden and
Concealed until the damage is beyond repair, and as it affects the

Fig. 1.— Termes Jlavlpes: a, adult male; 7i, terminal abdominal segments of same from below;
c, same of female; d, male, side view, somewhat inflated by treatment with ammonia; e,
abdomen of female, side view; /, tarsus, showing joints and claw; a, d, c, enlarged; b, c, /,
greatly enlarged (original).

integrity of the building itself as well as its contents, the importance
of the insect becomes very evident. Fortunately it is not often
present in the North in houses, but as the Tropics are approached
the injuries from it in dwellings or other structures of wood are of
common experience and often of the most serious nature, causing
the sudden crumbling of bridges, wharves, and settling of floors or
buildings.

The term " white ant," by which this insect is universally known,
is entirely inappropriate in so far as it indicates any relationship with
the true ants. Strictly speaking, the white ant is not an ant, but
belongs with the Neuroptera and is allied to the dragon flies and
May flies. The only analogy with ants is in superficial resemblance

and in the social habits of the two groups, in which great similarity
exists. The popular acquaintance with the termite or white ant is
mainly derived from witnessing its nuptial spring night, when the
small, brown, ant-like creatures with long glistening white wings
emerge from cracks in the ground or from crevices in buildings,
swarming out sometimes in enormous numbers, so that they may
often be swept up by the quart. These winged individuals are not
the ones which do the damage, but are the colonizing form. The
real depredators are soft-bodied, large-headed, milky- white insects,
less than a quarter of an inch in length, which may often be found
in numbers under rotting boards or in decaying stumps. These last
are the workers and soldiers (fig. 4, c and d), and constitute the bulk
of the colony for most of the year, the winged migrating forms,
consisting of the sexed individuals, appearing normally only once a
year, usually in April or early in May.

The white ants present, in an entirely distinct order of insects,
another of those most curious problems of communal societies which
find so many examples among the ants, bees, and wasps. A colony
of white ants includes workers, soldiers, the young of the various
forms, and, at the proper season of the year, the winged males and
females ; also a single parent pair, the specially developed king and
queen. In the case of the common white ant of this country
(Termes flavipes), the fully developed queen or mother of the
colony, swollen to great size by her enormous ovary development, and
her consort, the fully developed but much smaller king or male,
have never been found in the white ant communities, and this in
spite of the great numbers of the flying stage of both sexes that
appear every spring. The soldiers or workers are degraded or unde-
veloped individuals of both sexes, differing in this respect from ants
and bees, in which the workers are all undeveloped females.

The economy of the termites is almost exactly analogous to that
of the ants and bees. The workers attend to all the duties of the
colony, make the excavations, build the nests, care for the young,
and protect and minister to the wants of the queen or mother ant.
In this they are assisted somewhat by the soldiers, whose duty,
however, is also protective, their enormous development of head and
jaws indicating their role as the fighters or defenders of the colony.
Both the workers and soldiers are blind. The colonizing individuals
differ from the others in being fully developed sexually and in
possession of veiy long wings, which normally lie flat over each
other, the upper wings concealing the lower, and both projecting
beyond the abdomen. These wings have a very peculiar suture
near the base, Avhere they can be readily broken off, leaving mere
stumps. At the time of the spring flight the winged individuals
emerge from the colony very rapidly, frequently swarming in clouds

out of doors, and after a short flight fall to the ground and very
soon succeed in breaking off their long, clumsy wings at the suture
referred to. In this swarming or nuptial flight they come out in
pairs, and under favorable conditions each pair might become
especially developed, as described above, and establish a new colony,
but in point of fact this probably rarely, if ever, happens. They
are weak flyers, clumsy, and not capable of extensive locomotion on
foot, and are promptly preyed upon and destroyed by many insec-
tivorous animals, and rarely indeed do any of the individuals escape.
Theoretically, if one of these pairs succeeded in finding a decaying
stump or other suitable condition at hand, they would enter it, and
the king and queen, being both active, would attend to the wants
of the new colony and superintend the rearing of the first brood of
workers and soldiers, which would then assume the laborious duties
of the young colony. Thereafter the queen, by constant and liberal
feeding and absolute inaction, would increase immensely, her abdo-

Fig. 2.— Termes flavipes: a, head of winged female viewed from above; b, same from below,
with mouth-parts opened out— greatly enlarged (original).

men becoming many hundred times its original size. She would
practically lose the power of locomotion and become a mere egg-
laying machine of enormous capacity. Allied species whose habits
have been studied in this particular indicate an egg-laying rate of
60 per minute, or something like 80,000 per day.

In the absence of a queen, however, white ants are able to develop
from a very young larva or a nymph of what would otherwise
become a winged female what is known as a supplementary queen,
which is never winged and never leaves the colony. This supple-
mentary queen (fig. 4, a), for the discovery of which we are indebted
to the late H. G. Hubbard, is smaller than the perfect sexed queen,
but subserves all the needs of the colony in the matter of egg laying,
and is the only parent insect so far found in the nests of the common
white ant in this country. Whether a true queen exists or not is,
therefore, open to question ; if not, all the individuals which escape
in the spring and summer migrations must perish, and this swarm-
ing would, therefore, have to be considered a mere survival of a

once useful feature in the economy of this insect, now no longer, or
rarely, of service.

The normal method of the formation of new colonies is probably
by the the mere division or splitting up of old ones — their galleries
and branch colonies extending great distances from the home
colony — or the carrying of infested logs or timbers from one point
to another.

The development of these curious insects is very simple. There
is scarcely any metamorphosis, the change from the young larva to
the adult being very gradual and without any marked difference in
structure. They feed on decaying wood or vegetable material of
any sort, and are able to cany their excavations into any timbers
which are moistened, or into furniture, books, or papers stored in
rooms which are at all moist. Their food is the finely divided
material into which they bore, and from which they seem to be able
to extract a certain amount of nourishment, probably from the
moulds and ferments generated in the moistened vegetable material,
since they redevour the same material several times. Bearing out
this theory, tropical species are known to grow great mushroom beds
artificially on the product of which they largely subsist. The white
ants are also somewhat cannibalistic, and will devour the superflu-
ous members of the colony without compunction, and normally con-
sume all dead individuals, cast skins, and other refuse material.
They are capable also of exuding a sort of nectar, which is used to
feed the young and the royal pair, and which they also generously
give to each other.

All except the migrating winged forms are incapable of enduring
full sunlight, and the soft, delicate bodies of the workers, soldiers
and young rapidly shrivel when exposed. In all their operations,
therefore, they carefully conceal themselves, and in their mining of
timbers or books and papers the surface is always left intact, and
whenever it is necessary for them to extend their colonies it is done
only under the protection of covered runways, which the}7 construct
of particles of comminuted wood or little pellets of excrement. In
this way the damage which they are doing is often entirely hidden,
and not until furniture breaks down or the underpinning and timbers
of houses or floors yield is the injury recognized. The swarming of
winged individuals in the early summer, if in or about houses, is an
indication of their injurious presence and warrants an immediate
investigation to prevent serious damage later on.

The common termite of America is very widespread, occurring
from the Atlantic to the Pacific and from Canada southward to the
Gulf. It has been found on the mountains of Colorado and Wash-
ington at a height of over 7,000 feet. In prairie regions it may often
be seen during the swarming season issuing from the ground at fre-

yll,-

quent intervals over large pasture tracts, where it must feed on the
roots of grass and other herbage. It has also been carried to other
countries and is a common and often very injurious enemy of build-
ings and libraries in Europe. A closely allied and equally injurious
European species ( Termes lucifugus) has also been brought to this
country in exchange for ours, but compared with our own species is
somewhat rare though already widely distributed. In this country
serious damage to buildings from the white ant has not been of com-
mon occurrence, especially in the North, except in some notable
instances. In Europe our species has caused greater damage, and
some years ago gained access to one of the Imperial hothouses at
Vienna, and in spite of all efforts to save the building it was neces-
sary ultimately to tear it down and replace it with an iron structure.
In this country instances are on record of very serious damage to
books and papers. An accumulation of books and papers belonging
to the State of Illinois was thor-
oughly ruined by their attacks. A
school library in South Carolina,
which had been left closed for the
summer, was found on being opened
in the autumn to be completely eaten
out and rendered valueless. In the
Department of Agriculture an accu-
mulation of records and documents
stored in a vault which was not
thoroughly dry, and allowed to re-
main undisturbed for several years,
on examination proved to be thor-
oughly mined and ruined by white
ants. Humboldt, on the authority of Hagen, accounts for the raritj"
of old books in New Spain by the frequency of the destructive work
of these insects.

Numerous instances of damage to underpinning of buildings and
to timbers are also on record. The flooring of one of the largest
sections of the United States National Museum was for some years
annually undermined and weakened by a very large colony of these
pests which could not be located, and finally the authorities solved
the problem by replacing the wood floor with one of cement. A few
years ago it was found necessary to tear down and rebuild three
frame buildings in Washington in consequence of the work of this
insidious foe.

Damage of the sort mentioned has occurred as far north as Boston,
but, as stated, greatly increases as one approaches the Tropics, where
the warmth and moisture are especially suited to the development
and multiplication of this insect. There houses and furniture are

Fig. 3.— Termes flavipes: a, newly-hatched
larva; b, same from below; c, egg— all
enlarged to same scale (original).

never safe from attack. The sadden crumbling into masses of dust
of chairs, desks, or other furniture, and the mining and destruction
of collections of books and papers, are matters of common experience,
very little hint of the damage being given by a surface inspection,
even when the interior of timbers or boards has been thoroughly
eaten out, leaving a mere paper shell.

While confining their work almost solely to moistened or decaying
timbers or vegetable material of any sort, and books and papers that
are somewhat moist, they are known to work also in living trees, carry-
ing their mines through the moist and nearly dead heart wood. In
this way some valuable trees in Boston were so injured as to make
their removal necessary. In Florida they are often the cause of
great damage to orange trees, working around the crowns and in
the roots of trees. They are sometimes also the occasion of consid-
erable injury to other trees; and quite recently the writer received
information of injurious attack on pecan, chestnut, and walnut trees
at Augusta, Ga. They also cause loss in conservatories, attacking
cuttings and the roots of plants. Such injuries have been brought
to our notice several times by florists, and Mr. Chittenden, of this
office, informs me that they are apt to attack the large stems of
herbaceous plants like geraniums. The source of the Termites in
greenhouses is usually the more or less decayed woodwork of the
building itself or the plant benches, and they have even been found
working in label sticks, the removal of which gave relief from the
damage done to plants. In one instance, also, the Termites, coming
from the wooden benches, entered potted plants through the drain-
hole of the pots. In prairie regions their work is necessarily on the
roots and tubers of plants or the stems of grasses or other low-grow-
ing plants.

A very common form of injury to potatoes growing in rich soil or
where there is a considerable quantity of decaying vegetable matter
has often been noted, and the cause for it has been obscure or
assigned to insects innocent of the damage. That the white ant is
the culprit in this case was discovered by Mr. F. A. Marlatt, who
describes the injury to the tubers as having the form of scars or pits
covering the surface, the pits varying in shape from irregular holes
to long, irregular excavations sometimes extending far into the
potato, but commonly to a depth from an eighth to a fourth of an
inch. In all cases these pits are more or less overhung and covered
by the dead and dying skin, and are also lined with the cellular tis-
sue of potato, showing that the insect cares most for the starch and
water of the tuber. Such damage is liable to be found not only in
soil rich in vegetable matter but also in newly cleared soil or soil con-
taining the loose and decayed portions of trees, and in the instance
cited above was in soil recently cleared of an old apple orchard.

The white ant is not confined to country places, but is just as apt
to occur in the midst of towns, and especially in buildings which are
surrounded by open lawns containing growing trees and flower beds
richly manured.

REMEDIES AND PREVENTIVES.

The first means of protection consists in surrounding all libra-
ries or buildings in which articles of value are stored with clear

Fio. 4.— Termes fiavipes: a, queen; o, nymph of winged female; c, worker; cl, soldier— all en-
larged (original).

spaces and graveled or asphalted walks. The normal habit of these
insects of breeding in decaying stumps and partially rotted posts or
boards immediately suggests the wisdom of the prompt removal of
all such material which would otherwise facilitate the formation or
perpetuation of their colonies. Complete dryness in buildings is an
important means of rendering them safe from attack, and the pres-
ence of flying termites at any time in the spring or summer should
be followed immediately by a prompt investigation to locate the col-
ony and determine the possibilities of damage. The point of emer-
gence of winged individuals may approximately, though not always,
indicate the location of the colony, and if it can be got at by the

removal of flooring or opening the walls, the colony may be destroyed
by the removal of the decaying or weakened timbers and a thorough
drenching with steam, hot water, or, preferably, kerosene or some
other petroleum oil. The destruction of winged individuals as they
emerge is of no value whatever ; the colony itself must be reached
or future damage will not be interfered with in the least. If the
colony be inaccessible it may sometimes be possible to inject into the
walls or crevices, from which the winged individuals are emerging,
kerosene in sufficient quantity to reach the main nest, if the condi-
tions be such as to indicate that it may be near by, and by this means
most, if not all, of the inmates may be killed. Where floorings and
underpinnings, or books and papers, are badly infested and a whole-
sale treatment is imperative, the hydrocyanic-acid-gas fumigation is
to be recommended, first opening the floors at the neighborhood of
the colonies as nearly as can be determined, spreading out the books
and opening cases, wardrobes, etc. For full directions see Circular
No. 46 of this series.

The flooring of buildings in subtropical and tropical countries
should be of cement or stone, or at least the lower timbers and joists
should be imbedded in cement, and wherever it proves impossible to
prevent damage by the means indicated in a previous paragraph,
there is practically no other course than to replace the foundation
and floorings with stone, cement, or other form of stone composition.
Impregnation with creosote renders wood comparatively immune from
their attacks ; but this is too costly and difficult a process to come
into very general use. A heavy coating with tar of the foundation
timbers is often resorted to, and if carefully done protects the wood
as long as the coating is intact. Placing the legs of stands, bureaus,
etc., not in daily use, in small vessels containing kerosene oil will
protect such articles of furniture from the attacks of white ants in
the tropics. In the tropics, also, furniture should not lean against
or touch the walls, especially in houses of wood, and frequent exam-
inations should be made of libraries and stored papers.

Washington, D. C, Jane 30, 1902.

O